Device for regulating the flow of fuel injected into an internal combustion engine

ABSTRACT

Device for regulating the flow of fuel injected into an internal combustion engine. A rolling diaphragm is exposed on one side to the pressure prevailing in the induction pipe of the engine and on the other side to a pressure in the neighbourhood of atmospheric pressure by way of a conduit in which a valve device is inserted for normally closing the conduit. The valve device is shifted to the conduit opening position when a cam regulating the amount of fuel injected reaches the vicinity of an extreme position corresponding to predetermined conditions of engine operation.

United States Patent 1 1 Bone et al.

[ 1 Sept. 11, 1973 1 1 DEVICE FOR REGULATING TIIE FLOW OF FUEL INJECTED INTO AN INTERNAL COMBUSTION ENGINE [75] Inventors: Guy Boue, Bavans; Marcel Vidberg,

Montebeliard, both of France [73] Assignees: Automobiles Peugeot, Paris; Regie Nationale Des Usines Renault, Billancourt, France [22] Filed: May 15, 1972 211 Appl. No.: 253,422

[30] Foreign Application Priority Data June 17,1971 France 7121982 [52] US. Cl 123/97 B, 123/140 MP [51] Int. Cl. F02d H14 [58] Field of Search 123/97 B, 140 ML,

[56] References Cited UNITED STATES PATENTS 3,384,060 5/1968 Dangauthier 123/140 MP 2,752,906 7/1956 Nicolls 123/140 MP 270,334 H1883 Pike 251/323 FOREIGN PATENTS OR APPLICATIONS 1,558,460 12/1967 France 123/140 MP 89,396 4/1937 Sweden 123/140 MP Primary Examiner-Laurence M. Goodridge Assistant Examiner-Dennis Toth Att0rneyRobert S. Swecker [57] ABSTRACT Device for regulating the flow of fuel injected into an internal combustion engine. A rolling diaphragm is exposed on one side to the pressure prevailing in the induction pipe of the engine and on the other side to a pressure in the neighbourhood of atmospheric pressure by way of a conduit in which a valve device is inserted for normally closing the conduit. The valve device is shifted to the conduit opening position when a cam regulating the amount of fuel injected reaches the vicinity of an extreme position corresponding to predetermined conditions of engine operation.

6 Claims, 2 Drawing Figures strs'i, 79s

PATENTEU SEP! I I975 DEVICE FQR RI'ZGULA'IING THE FLOW F FUEL INJECTEI) INTO AN INTERNAL COMBUSTION ENGINE The present invention relates to an improvement in the device for regulating the flow of fuel injected into an internal combustion engine disclosed in the French Pat. No. 1,558,460 filed by the Applicants.

In such a device, the regulation is achieved by means of a diaphragm which is rollable and subjected on one side to the pressure prevailing in the inlet or admission pipe of the engine and on the other side to a pressure intermediate between the foregoing pressure and atmospheric pressure, the diaphragm acting itself on a cam which regulates the amount of fuel injected.

It is moreover known that, in a vehicle provided with a petrol injection engine, when the driver releases the accelerator pedal while the engine is operative beyond a certain speed, the injection must be completely out off. Now, the devices regulating by means of a cam do not produce a sufficiently distinct cutting off and resumption for the injection so that, for certain engine speeds, sporadic injections might occur which result in unpleasant driving conditions and an emission of imperfectly burnt gases. This is, for example, the case when the vehicle travels down hill, when the speed of vehicle is such the speed of the engine is in the neighbourhood of that at which the injection must be cut off.

An object of the present invention is to overcome this drawback and to achieve distinct cutting off and resumption of the injection when predetermined conditions of operation of the engine are reached.

This is achieved by providing a conduit which connectsto an enclosure, in which prevails a pressure in the neighbourhood of atmospheric pressure, the chamber' partly defined by the diaphragm and in which usually prevails the pressure intermediate between atmospheric pressure and the pressure prevailing in the inlet pipe, this conduit being normally maintained closed by a closing device which is adapted to be shifted to its opening position when said cam reaches the vicinity of an extreme position corresponding to predetermined conditions of operation.

In this way there is obtained a staggering between the value of the depression in respect of which the injection is cut off and that which corresponds to the resumption of the injection and consequently a difference of engine speed between the cutoff and the resumption of the in-- jection which enables the aforementioned drawbacks to be avoided.

Further features and advantages of the invention will be apparent from the ensuing description with reference to the accompanying drawing.

In the drawing:

FIG. 1 is an assembly view of the regulating device, and

FIG. 2 is a sectional view, on an enlarged scale, of the closing means and the mechanism for actuating the latter.

FIG. 1 shows a regulating device of the general type described in the aforementioned patent comprising a case 1 consisting of a body 1a and a cap 1b assembled by means of flanges 2a, 2b. Between these two flanges there is clamped the edge portion of a rollable diaphragm 3 which constitutes a movable member which defines with the inner wall of the cap lb a first chamber 4 and defines with a transverse partition wall 16 of the case a second chamber 17. In the first chamber 4 there prevails a pressure intermediate between atmospheric pressure and the pressure prevailing in the inlet or admission pipe Ill downstream of the butterfly valve or throttle l2, whereas in the second chamber I7 there prevails said pressure prevailing in the inlet pipe. The diaphragm 3 is intergral with a rod 21 whose free end acts on a regulating means which controls the flow of an injection pump and comprises in the known manner a plunger or piston 24 controlled by a push-rod 25 which is shifted by a rotatable cam 26, the variation in the amount of fuel injected for each displacement of the plunger 24 being achieved by varying the position of an end-of-travel abutment 27 for the plunger which is biased by a spring 28. The abutment 27 is constituted by a pivotable lever 29 whose free end defines a curved ramp constituting a cam 30 of suitable profile against which the end of the rod 21 bears through rolling ball means as shown in FIG. ii. For each cylinder of the engine there is provided a plunger such as the plunger 24 with which are associated an inlet valve Ca and a delivery valve Cr. The abutment 27 is common to all of the injection plungers.

According to the invention, the chamber 4 is connected by a conduit to a closing or valve device 101 which is fixed to the body of the injection pump, this device being connected by a second conduit 102 to an enclosure (not shown) in which prevails a pressure in the neighbourhood of atmospheric pressure. This enclosure can be constituted by the air inlet silencer immediately downstream of the air filter (not shown).

The closing or valve device 101 will now be described in more detail. The device comprises a body 103 fixed to the body of the injection pump by means of screws 103a. The body 103 has a stepped bore or aperture 104, 105 and an enlarged bore portion 106 which is screwthreaded and in which is screwthreadedly engaged a housing 107 the position of which determines the regulation of the device. The housing is held in position on its screwthreading by a deformation of the valve body achieved by clamping by means of a screw 10% a slot W9 formed in the body. A seal is provided between the housing 107 and the two portions 104, 1l05 of the bore by means of two sealing rings 110, Mill received in grooves 112, 113 in the housing.

The regulating housing is hollow and constitutes a cup in the bottom of which is provided an aperture 114 for the passage of a push-rod MS with provision of clearance. This push-rod is disposed in front of the lever 29 and extends through the case l and the body of the closing device through sealing means 116. A spring 117 bearing against a ring 118 biasesthe pushrod to the right as viewed in FIGS. I and 2, that is, to a position corresponding to closure of the closing device. The housing 1107 also has lateral passages 119 which put its inner cavity 120 in communication with the chamber 121 defined between the two sealing rings 110, 111 with which the conduit 102 also communicates. A plug 1122 is a drive fit in the regulating housing and includes a bore 123 in which is guided the stem of a valve member 1124 which has an annular sealing element 125 which cooperates with the end of the housing 107 and constitutes a seat around the aperture 114. A spring 1127 biases the valve member towards its closing position. The chamber 128, defined by the end of the housing and the valve body, communicates by way of the conduit MM]! with the chamber 4 of the regulating device described hereinbefore.

It is unnecessary to describe in detail once again the operation of the regulating device proper and the following description will be limited to the novel aspects.

In the position shown in the drawing, the abutment 27 is spaced away from the push-rod 115 so that the valve member 124 bears against its seat 107. The conduit 100 is closed and the chamber 4 is subjected, as described in the French Pat. No. 1,558,460, to a pressure intermediate between atmospheric pressure and the pressure prevailing in the inlet or admission pipe of the engine.

When the user releases the accelerator pedal while the engine is running at a relative high speed, the lever 29 carrying the cam 30, which determines the richness of the fuel mixture, pivots in the direction of arrow F so as to decrease the amount of fuel injected. When this cam reaches the vicinity of its extreme position, the lever 29 depresses the push-rod 115 and this shifts the valve member 124 to the left, as viewed in FIG. 2, and puts the chambers 12] and 128 in communication with each other. In this way the chamber 4 of the regulating device is suddenly put in communication with a pressure in the neighbourhood of atmospheric pressure. The diaphragm 3 and the rod 21 connected to the latter are shifted rapidly downwardly and this causes the cam 30 and the lever 29 to pivot and cut off the injection of fuel in a precise manner.

On the other hand, in operation in the opposite way, that is, when the injection is resumed, this device has no effect on the amount of fuel injected. in this way the drawbacks described in the preamble of the present specification are avoided without introducing any additional drawback, while employing a very simple device which does not substantially increase the cost of the system and does not affect the reliability.

We claim: 1. A device for regulating the flow of fuel injected into an internal combustion engine by a fuel injecting system, comprising means defining a first chamber for connection to an induction pipe of the engine so as to be exposed to the pressure prevailing in the induction pipe, a first movable member having a first face defining a movable wall of the first chamber, means defining a second chamber, the movable member having a face opposed to said first face defining a movable wall of the second chamber, the movable member being movable with respect to the first chamber and second chamber between a first position and a second position, means for regulating the amount of fuel injected into the engine upon each injection effected by the injecting system, cam means operatively connecting the movable member to the regulating means so that movement of the movable member achieves a variation of the amount of fuel injected between a maximum amount in said first position and zero amount in said second position of the movable member, a conduit communicating with the second chamber for connection to an enclosure in which prevails a pressure in the neighbourhood of atmospheric pressure, a valve device inserted in the conduit for normally closing the conduit, and means associated with the cam means for shifting the valve device to a conduit opening position when the movable member, in moving toward said second position, reaches a position in the vicinity of said second position.

2. A device as claimed in claim 1, wherein the cam means comprise a second member movable by movement of the first member between said first and second positions and the means associated with the cam means comprise a push-rod operatively connected to the valve device and engageable by the second member.

3. A device as claimed in claim 1, wherein the valve device comprises a hollow body, a hollow housing mounted in the body, the body and the housing defining a third chamber, means defining within the housing a fourth chamber, the third chamber and the fourth chamber respectively communicating with a downstream part of the conduit and an upstream part of said conduit, the housing having an end wall defining an aperture putting the third chamber and fourth chamber in communication with each other and constituting a valve seat, a valve member co-operative with the seat for selectively preventing and allowing the communication between the third chamber and the fourth chamber according to the position of the valve member.

4. A device as claimed in claim 3, wherein the housing is mounted to be adjustable in position in the body so as to enable the instant when the valve member opens said aperture to be determined with precision.

5. A device as claimed in claim 3, comprising a plug engaged in the housing and defining the fourth chamber, a cavity in the plug, a stem portion on the valve member and guided in the cavity in the plug, and resiliently yieldable means interposed between the plug and the valve member and biasing the valve member to a position for closing the aperture.

6. A device for regulating the flow of fuel injected into an internal combustion engine by a fuel injection system, comprising means defining a first chamber for connection to an air-induction pipe of the engine so as to be exposed to the pressure prevailing in the induction pipe, a movable member having a first face defining a movable wall of the first chamber, means defining a second chamber, the movable member having a second face which is opposed to said first face and defines a movable wall of the second chamber, the movable member being movable between a first position and a second position with respect to the first chamber and second chamber, means for regulating the amount of fuel injected upon each injection effected by the injection system and associated with the movable member so that the movable member actuates the regulating means and achieves a variation of the amount of fuel injected between a maximum amount in said first position of the movable member and zero in said second position of the movable member, means for putting the second chamber in communication with a pressure in the neighbourhood of atmospheric pressure and adapted and arranged and associated with the movable member to be normally inoperative but rendered operative when the movable member, in moving toward said second position, reaches a position in the vicinity of said second position. 

1. A device for regulating the flow of fuel injected into an internal combustion engine by a fuel injecting system, comprising means defining a first chamber for connection to an induction pipe of the engine so as to be exposed to the pressure prevailing in the induction pipe, a first movable member having a first face defining a movable wall of the first chamber, means defining a second chamber, the movable member having a face opposed to said first face defining a movable wall of the second chamber, the movable member being movable with respect to the first chamber and second chamber between a first position and a second position, means for regulating the amount of fuel injected into the engine upon each injection effected by the injecting system, cam means operatively connecting the movable member to the regulating means so that movement of the movable member achieves a variation of the amount of fuel injected between a maximum amount in said first position and zero amount in said second position of the movable member, a conduit communicating with the second chamber for connection to an enclosure in which prevails a pressure in the neighbourhood of atmospheric pressure, a valve device inserted in the conduit for normally closing the conduit, and means associated with the cam means for shifting the valve device to a conduit opening position when the movable member, in moving toward said second position, reaches a position in the vicinity of said second position.
 2. A device as claimed in claim 1, wherein the cam means comprise a second member movable by movement of the first member between said first and second positions and the means associated with the cam means comprise a push-rod operatively connected to the valve device and engageable by the second member.
 3. A device as claimed in claim 1, wherein the valve device comprises a hollow body, a hollow housing mounted in the body, the body and the housing defining a third chamber, means defining within the housing a fourth chamber, the third chamber and the fourth chamber respeCtively communicating with a downstream part of the conduit and an upstream part of said conduit, the housing having an end wall defining an aperture putting the third chamber and fourth chamber in communication with each other and constituting a valve seat, a valve member co-operative with the seat for selectively preventing and allowing the communication between the third chamber and the fourth chamber according to the position of the valve member.
 4. A device as claimed in claim 3, wherein the housing is mounted to be adjustable in position in the body so as to enable the instant when the valve member opens said aperture to be determined with precision.
 5. A device as claimed in claim 3, comprising a plug engaged in the housing and defining the fourth chamber, a cavity in the plug, a stem portion on the valve member and guided in the cavity in the plug, and resiliently yieldable means interposed between the plug and the valve member and biasing the valve member to a position for closing the aperture.
 6. A device for regulating the flow of fuel injected into an internal combustion engine by a fuel injection system, comprising means defining a first chamber for connection to an air-induction pipe of the engine so as to be exposed to the pressure prevailing in the induction pipe, a movable member having a first face defining a movable wall of the first chamber, means defining a second chamber, the movable member having a second face which is opposed to said first face and defines a movable wall of the second chamber, the movable member being movable between a first position and a second position with respect to the first chamber and second chamber, means for regulating the amount of fuel injected upon each injection effected by the injection system and associated with the movable member so that the movable member actuates the regulating means and achieves a variation of the amount of fuel injected between a maximum amount in said first position of the movable member and zero in said second position of the movable member, means for putting the second chamber in communication with a pressure in the neighbourhood of atmospheric pressure and adapted and arranged and associated with the movable member to be normally inoperative but rendered operative when the movable member, in moving toward said second position, reaches a position in the vicinity of said second position. 